Whats the deal with a Nitrogen tire inflation system?

I have been hearing about people putting Nitrogen in the car tires and was wondering what the deal was? I thought that was something Nascar drivers did and I have no idea what the advantages are for the regular guy.

Nitrogen tire inflation systems are becoming increasingly common in professional auto shops as a way to increase fuel effeciency and tire life for their customers. All that happens is a Nitrogen tire inflation system fills your car's tires up with inert Nitrogen instead of plain old air from the shop air compressor. One advantage is Nitrogen is less prone to escape from your tire. This means your car's tires will maintain optimum pressure for longer periods of time. Also, the oxygen in regular air is corrosive to the tires rubber and valve stems. So by using Nitrogen in your car's tires, their life will be prolonged and even your fuel efficiency will increase over time.